1. Field of the Invention
This invention relates to safety apparatus, and more particularly, to a system for warning that a portion of a crane or other construction equipment is near an electrical power line.
2. Description of the Prior Art
In the construction industry it is often necessary to operate cranes and excavators in areas having nearby high voltage power lines which must not be contacted by the crane or the crane boom. In the past, numerous accidents have occurred when the crane boom, the crane lifting lines, or boom support lines and gantry have come into contact with electrical power lines, and operators have been killed by electrocution. As a result industry and government regulators have recommended that a person be stationed on the ground near an operating crane to observe the clearance between the crane and electrical power lines and to give timely warnings of danger for all operations where it is difficult for the operator to monitor the desired clearance by visual means. In practice, it has been found that a ground observer is not a reliable safety element and accidents have occurred when the ground observer was not present or when his attention was diverted.